Their goal for some time now[1] is to keep cash flowing through the military-industrial-complex. They obviously don't have any kind of focus on actual intelligence work, or they wouldn't be so bad at basic practices like compartmentalization[2]. Even the ways they could abuse their surveillance capabilities seem to be more of a "bonus". They could be much worse, but that would distract form their business of piping cash to their "contractor" friends.

Interestingly, the recent mess the EFF has been reporting on (Jewel v NSA) where they tried to retcon the public court record has - in the public court record - the DOJ lawyers delivering[3] and incredible Freuidan-slip. While arguing that basically nobody can ever have standing to challenge their Section 215 based activities, they mention this: (caps in original, emphasis mine)

    ALL THESE TERRIBLE DISCLOSURES THAT OCCURRED OVER THE PAST YEAR -- IN FACT,
    THIS IS THE ONE YEAR ANNIVERSARY -- DISCLOSURES THAT WE ARE CONVINCED THAT
    HAVE SERIOUSLY HARMED THE NATIONAL SECURITY OF THIS *COMPANY*, WE HAVE CONTINUED
    TO PROTECT THE IDENTITY OF PARTICULAR TELECOMMUNICATION CARRIERS THAT ARE
    ALLEGED TO HAVE ASSISTED THE NSA,

"national security of this company". wow.

[1] According to William Binny and others. This recent interview mentions it, as to many others.

http://www.dw.de/binney-the-nsas-main-motives-power-and-mone...

[2] For example, how the hell did Snowden even have access to that many sensitive docs? Even as a sysadmin, he didn't "need to know" a lot of that. They use to take that kind of practice deadly seriously.

[3] https://www.techdirt.com/articles/20140813/23203228207/unsea...